Soil Problems:
pH
Drainage
Compaction
Volumes

Girdling Root Syndrome:
Genetically induced
Culturally induced

Deicing Salt:
Run-off
Spray/drift

Weather Extremes:
Winter stem damage

Mechanical Damage:
Mower/string trimmer complications
Construction damage

Tree Installation Problems 
Depth
Much tree mortality may be attributed to installation or tree harvesting practices that place the root (trunk) collar area of newly planted trees several inches below the landscape grade. This is more of a problem when trees are planted in clay soils, poorly-drained, and/or very compacted soils, but can be aggravated by surface mulches, or turf established to the stem of the tree. 

Causes: a) Trees planted with the root collar area 6+ inches below the landscape grade. In reality, problems may arise with some species when only 1-2 inches too deep. 
b) B&B or machine-dug trees harvested with excessive amounts of soil over the root collar area [a result of "hilling-up" cultivation practices that smother weeds in the field]. 
c) Burying of the graft union-treating trees as some gardeners treat hybrid tea rose bushes. 
d) Planting holes dug extra deep, with loosened soil "cones" constructed in the hole center. Trees [especially B&B or machine-dug trees] planted on these "cones" eventually settle too much, and in effect plant themselves too deep. 
e) Annual accumulations of mulch, in particular, fine-textured mulches

Damage: a) Restriction of water and oxygen to the fine root systems. 
b) Higher incidence of stem cankers and decay. 
c) Poor root system regeneration of transplanted trees. 
d) Gradual death of existing roots. 
e) Extended period of transplant shock. 
f) Lower tree vitality and reserve of energy. 
g) Increased vulnerability to biotic problems and environmental extremes. 
h) Higher incidence of adventitious root formation; these adventitious roots may often become encircling and girdling roots.

Symptoms: a) Nutrient deficiency symptoms. 
b) Scorch. 
c) Wilt. 
d) Tip dieback. 
e) Stag-heading. 
f) Stunt, foliar and annual growth rates. 
g) Adventitious rooting on many species. 
h) Early fall coloration and leaf fall. 
i) Decline in vitality, commonly slow and progressive. This may progess for 5-10 years.
j) Leaning. 
k) Chronic windthrow. 
l) Death. 

Interface Penetration
Trees planted in small planting holes, especially in soils that have been severely compacted, commonly exhibit transplant shock symptoms for unusually long periods. Sometimes they never recover completely and languish their entire lives. Roots can eventually penetrate the interface of the planting hole, that is, that point where the existing soil meets the prepared planting hole soil. However, when the existing soil is a very compacted clay, it may take several years for the new roots to penetrate extensively enough to support "normal' stem and canopy growth. Often, roots never penetrate the existing soil adequately, and the trees never look "normal." 

Causes: a) Existing soils are primarily clays, with very shallow organic horizons. 
b) Existing soils have been stripped of topsoil and compacted to meet engineering standards for construction. 
c) Existing soils are primarily clays and were subjected to extensive traffic compaction, especially during times of the year when the soils were wet. 
d) Trees have been moved with a tree spade directly into the clay and/or compacted soils. Planting holes have been dug with the tree spade and not modified or enlarged prior to insertion of the transplanted tree. 
e) Planting holes have been dug with vertical sides and only large enough to insert the soil ball/root system of the new tree.

Damage: a) Extended transplant shock period. 
b) Lengthy period of low vitality. 
c) Occasionally, encircling roots. 
d) Increased vulnerability to biotic problems and environmental extremes. 
e) Reduced [as compared to normal] fine root surface area and critical root zone. 
f) Reduced root:shoot ratio. 
g) Shorter lifespan. 

Symptoms: a) Scorching and wilting is chronic and annual. 
b) Nutrient deficiency symptoms. 
c) Tip dieback. This may appear as chronic winter damage. 
d) Increased stem cracking during late winters. 
e) Slower sealing-over of pruning wounds. 
f) Decline syndrome.
g) Stag-heading. 
h) Epicormic watersprouting. 
i) Chronic windthrow and leaning. 
j) Girdling roots. 

Transplant Shock
Transplant shock is unavoidable; transplant shock that continues for years and years is not acceptable but unfortunately is very common. Trees that have had their roots severed during the harvesting process must reestablish an adequate root system before the entire plant can begin normal growth. During this period of system 'shock' it is normal to observe stress symptoms. Often, field-grown trees that are B&B or machine harvested only retain 5-10% of their original root system in the soil ball. As a rule of thumb, the transplant shock period lasts one year for each one inch of stem caliper. 

Even trees that have been container-grown and theoretically retain 100% of their root system suffer some transplant shock. They have been grown under intensive cultural conditions of regular irrigation and fertilization, and now have been thrust into the much harsher environment of the open landscape. 

Bare-root harvested trees usually have a higher percentage of their roots dug with the plants, and therefore should experience a milder form of transplant shock. Sometimes this happens. Unfortunately, bare-rooted trees are often poorly-handled prior to planting, and the more extensive root system dries out and dies. 

Causes: a) Removal of as much as 90-95 % of the root system as a result of the harvesting process. 
b) Plant roots are allowed to dry out and die. 
c) Container-grown plants are transplanted from uniquely optimal conditions to the sub-optimum conditions found in most landscapes. 
d) Plants are improperly handled following harvest: roots allowed to dry out; heavy soil balls are dropped and rolled to planting sites instead of carted. 

Damage: a) Reduced ability to take up water and nutrients. 
b) Increased vulnerability to biotic problems and environmental extremes. 
c) Reduced photosynthesis and accumulation of energy reserves. 
d) Reduced growth, especially root growth. 
e) Abnormally high shoot:root ratio leaves the trees more vulnerable to total failure.

Symptoms: a) Overall stunt: leaves, annual shoot growth, caliper growth. 
b) Wilt, scorch. 
c) Early leaf coloration; early leaf fall. 
d) Suckering and/or epicormic watersprouting. 
e) Reduced flowering, and/or quality of flowers. 
f) Abnormally high amount of winter killed twigs and/or buds. 

Girdling Wires
Wires, synthetic ropes and synthetic plant name tags left on trees and shrubs do not usually result in high mortality rates, although it does happen. More commonly, they result in girdled branches or stems that disfigure the plant. Any synthetic material left on plant branches or stems may sooner or later cause phloem girdling at the least, and branch or stem failure or death at the worst. Often, wires become imbedded in the sapwood of a branch or stem and the plant appears to have overcome the obstruction. Unfortunately, this is a weak point that frequently is a point of structural failure during windstorms, ice storms or after heavy and wet snows. 

Girdling from wires and other synthetic materials is a particular problem on plants that are in ideal growing environments. Young plants when provided with good soils and care can begin putting on stem and branch caliper relatively soon after planting. It is not uncommon to see girdling damage after only one season in the landscape when the growing conditions are superior and the plants are vigorously growing. More commonly, however, girdling from these materials take two or more years to finally cause noticeable damage, and usually it is too late to correct the problem. 

Causes: a) Synthetic materials that do not break down rapidly in natural light have not been removed at planting. 
b) Natural materials such as jute rope that have been wound around tree trunks on balled and burlapped or tree spade dug trees and left exposed to sunlight and drying air may not break down fast enough to avoid compression of the new sapwood. Many times this does not become obvious until the tree fails several years after planting. 
c) Trees that have been staked or guyed at planting, and have had the attachment wires secured too tightly around the tree stem, even if the wires have been inserted through lengths of hose. 

Damage: a) Phloem girdling, sapwood compression; restriction of photosynthates flowing down. 
b) Death of branches or stems and canopy above the girdled point.
c) Reduced root regeneration and stem caliper growth below the girdled point.
d) Failure [breakage] of the branch or stem at the girdled/compressed point.
e) Potential loss of natural form of excurrent trees if the stem was girdled or compressed.

Symptoms: a) Pinched appearance to the stem or branch at the point of constriction
b) Swollen appearance above the point of constriction.
c) Leaf scorch, wilting, stunt.
d) Flagging of branches or canopies; tip dieback; stagheading.
e) Epicormic watersprouting or excessive suckering below the point of constriction.
f) If bracnhes or stems break at the compressed or girdled point, breaks appear clean rather than torn or ragged.

Mulch
Damage from incorrect mulch applications around trees and shrubs is becoming more common as homeowners and professional recognize the many benefits of mulching plants. Problems may arise, however, under certain circumstances: excessively deep applications of fine-textured organic mulches, organic mulches piled up against the trunk of young and/or thin-barked trees and shrubs, and plastic groundcovers applied before the topdressed mulch, especially when the plastic is in contact with heavy, clay soils.

Causes: a) Deep applications of fine-textured mulches over the fine root system may restrict soil oxygen and water. 
b) Plastic groundcovers placed on heavy, clay soils to prevent weeds from growing up through the mulch may create "glazed" interfaces [soil/plastic interface]. The soil near the plastic commonly becomes saturated which restricts soil oxygen. 
c) Organic mulches piled up against the trunks or stems of young or smooth- barked trees and shrubs retain unusually high amounts of moisture, do not allow the bark to dry out, and restrict natural light from the trunk or stem

Damage: a) Fine root mortality. Loss of part or all of original branch root system. 
b) Inadequate oxygen diffusion rates. 
c) Excessive formation of adventitious roots off stems covered by mulches. 
d) Mulch girdling; a phenomena where the stem caliper grows normally above the mulch line, but puts on little stem caliper below the mulch line. 
e) Some species are more prone to girdling root formation under deep mulch conditions.
f)  Under plastic groundcovers on heavy, clay soils, many trees and shrubs produce extremely shallow and large branch roots.
g) Reduced fine root development. 
h) Increased vulnerability to stem canker pathogens and decay. 

Symptoms: a) Blackened roots. 
b) Scorch, wilt, nutrient.deficiency, early fall color, early leaf drop, chronic and excessive tip die-back, flagging, stagheading.
c) Overall stunt; decline. 
d) Mulch girdled stems. Little to no stem caliper growth below the mulch line. During summer windstorms, these trees are more likely to "fail" at that point of "constriction." 
e) Unstable trees or shrubs. Poorly anchored, they lean or windthrow more commonly than others. 
f) Excessive adventitious rooting off stems below the mulch line. 

Soil Problems
pH
Soils in the upper Midwest vary widely in their natural pH. Urban soils are just as variable and more unpredictable. It is not unusual for a soil pH range from 6.5 to 8.5 within a neighborhood. This is due primarily to buried construction debris or other materials, such as wood ash; or in new developments where certain areas were used as clean-out sites for concrete trucks, plastering equipment, and masonry cleaners. 

Causes: a) Natural variability in soils, due to parent materials. 
b) In urban areas, the burial or deposition of foreign materials and chemicals 

Damage: a) Reduced plant vitality; reduction of photosynthates. 
b) Increased vulnerability to biotic problems and environmental extremes 
c) Occasional toxicity damage. 

Symptoms: a) Specific nutrient deficiency symptoms, ranging from off-colored leaves, lack of flowering/fruit production, foliar scorching to malformed leaves and growth habits. 
b) Overall stunt. 
c) Chronic problems with biotic pathogens and insects. 
d) Decline.
e) Excessively prolonged transplant shock periods. 
f) Chronic winter damage [esp. dieback]. 

Drainage
Poor drainage is one of the primary causes of low plant vitality and high mortality rates of many urban trees. With urban soils, poor drainage is often a chronic condition, especially in public areas, such as boulevards and planting pits, and new construction sites. 

Causes: a) High water tables; either natural, periodic or induced from alterations of watersheds. 
b) Natural hardpans or induced hardpans from cultivation techniques. 
c) Compacted subsoils to meet engineering standards for construction. 
d) Poor plant-to-site decisions. The soil isn't the problem ... the plant selection is!

Damage: a) Low plant vitality; reduced photosynthesis, reduced energy reserve levels 
b) Increased vulnerability to problems from biotic agents or environmental extremes. 
c) Extensive root loss. 
d) Loss of stability. 
e) Death. 

Symptoms: a) Scorch, wilt, early leaf coloration, early leaf fall, nutrient deficiency symptoms. 
b) Excessive winter damage: stem cracking, twig dieback. 
c) Blackened roots. 
d) Flagging; stagheading. 
e) Higher incidence of windthrow or leaning. 
f) Higher incidence of girdling roots. 
g) Death. 

Compaction
Soil compaction, especially with clay soils in urban areas is a common condition that results in chronic problems with low tree vitality and secondary problems. Clay soils [clays, clay- loams] are the types of soils that experience the most problems with compaction. Sandy and organic soils usually don't compact as severely and for lengthy periods, therefore, there are fewer problems with trees grown in these soils even if they have been subjected to compaction.

Compacted clay soils cause plant problems in three ways: 1) reduced soil oxygen; 2) reduced soil moisture; and 3) increased resistance to fine root penetration. Sandy and organic soils may be compacted, but the structure of those soils allows roots to penetrate, even when bulk density measurements may be fairly high. Bulk density is a measurement of soil compaction, that is commonly used and commonly misinterpreted. Clay soils with high bulk density values are almost impenetrable by fine roots. Sandy soils with high bulk density values (sometimes even higher than compacted clays) are usually not root restrictive, due to the texture and structure of sandy soils. 

Bulk density values do provide a clue when diagnosing tree problems, however. in particular with clay soils, higher bulk density values are often associated with lower oxygen diffusion rate values. Low oxygen diffusion rate values have been shown to be directly related to low plant vitality, and may be a better measurement of a soil's ability to support plant life. Low oxygen diffusion rates are not just associated with compacted clay soils. Even sandy soils if saturated have low oxygen diffusion rates, and will not support the majority of trees and shrubs used in the landscape. 

Causes: a) Stripping of organic topsoils to clay layers, and compacting the subsoil to engineering standards to support foundations and road bases. 
b) Repeated equipment use over a common traffic pattern. This can occur on a construction site or in a corn field where tractors use the same paths annually. 
c) High levels of foot traffic, such as in parks or schools, especially on clay soils at times of the year when the soil is very moist. 
d) Very fine landscape grading of clay soils. 

Damage: a) Reduced soil oxygen and moisture. 
b) Increased resistance to new fine root penetration. 
c) Extended periods of transplant shock. 
d) Lowering of plant vitality and ability to store energy reserves. 
e) Increased vulnerability to biotic problems and environmental extremes. 

Symptoms: a) Scorch, wilt, nutrient deficiency symptoms, early fall coloration, early leaf drop. 
b) Excessive winter damage, twig dieback, stagheading. 
c) Overall stunt. 
d) Decline, death. 
e) Chronic problematic infections and infestations.

Volumes
Trees grown in planters, pots or below-ground pits [tree coffins] rarely are in rooting environments that are adequate in volume. Research has shown that most landscape trees need at least 300-1000 cubic feet of soil for normal growing conditions. The larger the tree species [maples, oaks, lindens], the more voiume is required. 

The reality of most tree containers is an average soil volume of 75-100 cubic feet, or enough to support a forsythia shrub. Low soil volumes compound all of the soil problems previously mentioned by adding another stress to the trees once they have filled the volumes with roots. 

Causes: a) Inadequate soil volumes provided in containers and tree pits for medium and large tree species survival. 
b) Poor plant selection for these 75-100 cubic foot plant coffins. Trees and shrubs naturally small in stature [crabapples] do not normally require very large [ > 500 cubic feet] volumes of soil. 
c) Often, the quality of the soil in these limited volumes is poor: compacted and poorly-drained. 

Damage: a) Limited carrying capacity for supporting plant life. A volume of soil has a limit to its nutrient and water-holding capacity. 
b) Smaller volumes are more vulnerable to environmental extremes, i.e., quick and deep freezes, and excessively high summer soil temperatures. 
c) Trees normally medium to large in size eventually fill the volumes with roots, can expand anymore, and stresses above-ground plant parts due to the limited moisture and nutrient uptake capabilities. 
d) Trees slowly decline in vitality. 

Symptoms: a) For trees normally medium to large in stature, leaf scorch, chronic wilting, and nutrient deficiency symptoms.
b) For trees grown in sidewalk-level street tree pits that are near major streets or parking areas, increased deicing salt symptoms from snow-melt run-off. 
c) Higher incidences of stem cracking, frost cracks, winter damage as twig die-back. 
d) Flagging, stagheading. 
e) Increased vulnerability to biotic problems and environmental extremes. 
f) Excessive suckering and epicormic watersprouting. 
g) Decline and death.

Girdling Root Syndrome
Genetically Induced
Certain trees chronically experience problematic girdling roots, and are theorized to be genetically prone to this condition. Topping this list are the maples, especially Norway maples. Other 'suspect' species include American beech, poplars and the littleleaf linden cultivar 'Greenspire.' 

Not all girdling roots are necessarily problematic. Only those that occur at the root collar area or above are considered chronically dangerous. Girdling roots that occur below the root collar area are not normally a threat to the tree's health or stability. It is also nearly impossible to look at a developing girdling root and predict that it will cause problems for the tree. It is more likely, however. 

Culturally Induced
Any tree can develop root systems that could eventually result in girdling root problems, depending on how they were grown and/or planted. Pot-bound plants often develop girdling roots if the roots are not pruned at planting time. Girdling roots can develop from poor planting techniques, such as "twirling" a bare-root system into a planting hole that is too- small for the roots, planting too deep, and planting in inadequate soil volumes. 

Causes: a) For genetically prone plants, simply cutting the branch roots during the harvesting operations may result in girdling roots. Most plants regenerate roots at acute angles off the branch roots. Trees such as Norway maples commonly regenerate roots that run tangential to the tree trunk and later become girdling roots. 
b) For culturally induced girdling, poor growing practices [allowing plants to become pot-bound]-, poor planting techniques [no root pruning of pot-bound plants, planting too deeply, "twirling" roots into small planting holes. 
c) Roots that girdle at the root collar area or above compress sapwood, and restrict the flow of photosynthates to the root system. 
d) Declining roots systems; insufficient root systems for supplying water and nutrients to the tree and supporting it physically.

Damage: a) Restriction of photosynthates to the root system. 
b) Root death. 
c) Loss of anchorage system. 
d) Structural weakness at the point of constriction. 

Symptoms: a) Scorch, early fall coloration, early leaf drop, localized damage symptoms
b)  Excessive twig dieback, stagheading. 
c) Thin appearance to crown, overall stunt. 
d) Little to no stem taper [buttressing] at ground level, or one-sided taper. 
e) Leaning. 
f) Vulnerability to other biotic problems and environmental extremes. 
g) Higher than normal incidences of winter damage: stem damage and dieback. 
h) Chronic windthrow or failure at the point of constriction. 

Deicing Salt
Run-off Salt
Snow melt from deicing salts, especially sodium chloride, may become problematic in sidewalk planting pits, edges of parking lots and sidewalks, and drainage ditches. High levels of soluble salts may accumulate and long-term decline of plant health begins. All forms of plants are affected by deicing salts, from turfgrass to trees and shrubs. 

Spray/Drift Salt 
Roadsalt spray or drift poses a more chronic threat to tree and shrub health than run-off salt. Most damage occurs within 65 feet of high volume, high traffic roads; however, damage is not uncommon for distances of 150 feet or more from high speed roads. Most trees and shrubs are susceptible to deicing salt spray damage. 

Causes: a) Heavy use of sodium chloride as a deicing agent. 
b) Run-off [melt-off] salt elevates soluble salt levels in soils. 
c) Heavy accumulations of run-off salt breaks down the structure of soils. 
d) Spray salt is more common on high volume, high speed roads. 
e) Spray salt may create high levels of soluble salts in the soil. 
f) Spray salt drift causes deposits of sodium chloride on buds and growing points of deciduous plants, and foliage of conifers that is directly toxic to plant materials. 

Damage: a) Disruption of water movement from soil to plant roots. 
b) Death of buds, growing points and foliage from direct chemical toxicity. 
c) Reduction in plant vitality. 
d) Breakdown of soils, leaving them more susceptible to drainage problems and reduced soil oxygen levels. 

Symptoms: a) Witches' brooming, increased suckering and epicormic watersprouting. 
b) Scorch, wilt, early fall coloration, early leaf fall, twig dieback.
c)  Overall stunt, decline. 
d) Increased vulnerability to other biotic problems and environmental extremes. 

Weather Extremes
Winter Stem Damage
Winter stem damage is usually labeled as frost cracking, bark splitting or- frost cankering. Most damage occurs in parts of the country where winters are characterized by long periods of snow cover with subsequent increased light reflection. 

Causes: a) Trees grown in exposed sites, such as boulevards, parking lot planting pits, or new landscapes. 
b) Poor plant selection. Trees selected for boulevards are commonly native to forested areas, not normally exposed to full sunlight. 
c) Plants that enter winter under water stresses are more vulnerable. 
d) Plants that are more prone to stem damage suffer more if they enter winter in any stressed condition. 
e) Warm winter sunlight warms up the southern and southwestern sides of young or smooth-barked trees. When the cold night temperatures cool the bark down to ambient temperatures, splitting of the bark occurs. 
f) Warm winter sunlight warms up tender, smooth bark, dehydrates it and results in cankering. 

Damage: a) Opening of wounds on tree stems. 
b) Wounds must compartmentalize and seal over, which requires energy drawn from the tree's energy reservoir. 
c) Wounded areas disrupt flow of materials in the phloem. 
d) Decay commonly results from wounded areas. 
e) Secondary infections commonly enter through wounds. 

Symptoms: a) Open splits or cracks on tree stems, especially on young trees or smooth- barked trees. Cracks may also occur on older trees that have been previously cracked, and originate from old cracks or previous "flush cut" pruning wounds.
b) Sunken, dead areas on stem.
c) Secondary canker infections.
d) Stem decay.
e) Excessive epicormic watersprouting.
f) Overall stunt.

Mechanical Damage
Mower and/or String Trimmer Damage
This is a very chronic and insidious landscape tree problem. Repeated damage from mowers slamming and gouging into tree trunks or tearing off bark with wheels and mowing decks is often on a weekly basis during the growing season. Mowers do not need to tear off bark to cause damage; simply banging into tender young bark and cambium may eventually kill the cambium or even girdle the stem. String trimmers are just as evil and damaging. Damage is particularly severe during the weeks of the early growing season and on thin, smooth-barked trees. Older, thicker-barked trees are less vulnerable to this problem.

Causes: a) Crushing of the cambium from banging equipment into trunks.
b) Tearing off bark and cambium from equipment.

Damage: a) Wounding of the cambium and sapwood.
b) Subsequent decay; interruption of the sapwood and heartwood.
c) Open wounds and decay drastically increase the strength loss percentage and create hazard trees.
d) Open wounds provide openings for secondary, canker-causing pathogens.
e) Interruption of the flow of photosynthates to the root system.
f) In some cases, girdling of the stem and complete restriction of photosynthates
g) Constant sealing over of wounds drains the energy reserve systems of trees.

Symptoms: a) Swollen, wounded areas from repeated wounding and callousing.
b) Leaf scorch, thin appearance to canopy, uneven fall coloring and leaf drop
c) Basal decay.
d) Under girdling conditions, overall stunt, wilt, scorch, die-back.
e) Tree failure during windy weather.
f) Excessive suckering and epicormic watersprouting.

Construction Damage
Several of the problems previously discussed may -also be associated with construction damage, in particular, soil problems. Mechanical damage, however, is usually the most consistent construction damage, and very often the most difficult to see and diagnose. This is because most of the damage occurs underground: mechanical damage to the root system, either as wounding of branch roots and root collars, or removal of major part of the root system.

Causes: a) Grade changes, especially the "cutting" part of cut and fill operations.
b) . Excavations for footings/foundations.
c) Installation of service lines via trenches.
Damage: a) Wounding of the woody roots, either as large, open wounds, or (more seriously) coarse cuts/rips/breaks of the roots from excavation equipment.
b) Higher incidences of root decay and secondary invasions by pathogens.
c) Removal of high percentages of the fine-root system, which results in a drastically reduced ability to absorb water and nutrients from the soil.
d) Serious reduction in plant vitality and energy reserves.
Symptoms: a) Early: wilting, flagging, tip dieback, off-color (dull) foliage.
b) Early fall coloration, early leaf drop; chronic wilt.
c) Late spring leaf-out.
d) Abnormally high incidences of winter damage.
e) Nutrient deficiency symptoms; overall stunt; chronic secondary invasions.
f) Clumped foliage growth appearance, due to epicormic watersprouting.
g) Stagheading; branch sloughing, chronic windthrow.

02/01/2009
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